Heavy rain prompts flash flood watch for Twin Cities, surrounding area

Heavy rain moved into the Twin Cities metro and surrounding areas on Thursday afternoon, with a thunderstorm shutting down some first-day activities at the Minnesota State Fair.

The precipitation, while much needed after a summer of drought conditions, was expected to bring the opposite problem, possibly dumping more than 3 inches of rain overnight. That prompted a flash flood watch for the metro and several counties around it.

The fair canceled its daily parade and several other entertainment events were paused during a brief but severe thunderstorm Thursday afternoon. A few hours later, a lightning flare-up led the fair to shut down the Skyride, SkyGlider and Space Tower for the rest of the night. The grandstand, where hundreds of people had gathered for a Miranda Lambert concert, was evacuated about 7:30 p.m.; it was not clear as this edition of the Star Tribune went to press whether the concert would still be held.

The flash flood alert is in effect through early Friday for portions of central, east, south, southeast and west central Minnesota, where a band of thunderstorms was moving Thursday evening.

Affected counties included Hennepin, Ramsey, Anoka, Washington, Pope, Stearns, Benton, Sherburne, Kandiyohi, Meeker, Wright, McLeod, Sibley, Carver, Scott, Dakota, Nicollet, Le Sueur, Rice, Goodhue, Blue Earth, Waseca, Steele, Faribault and Freeborn.

Heavy rain could also flood lower grounds on the western half of the State Fair area.

There's a 60% chance of thunderstorms before 10 a.m. Friday, a possibility of storms between 10 a.m. to 4 p.m. and then an increased likelihood after 4 p.m. Friday until 1 a.m. Saturday, the National Weather Service (NWS) said. Rainfall is expected to measure between a tenth to a quarter of an inch, and higher amounts if it storms.

On Saturday, there's a 50% chance of showers and thunderstorms after 1 p.m. in the metro area. Otherwise, it will be mostly sunny with a high of 87 degrees. There's an 80% chance of precipitation Saturday night with a chance of thunderstorms.

Sunday should clear up, with a high of 78 degrees and sunny skies. But showers could pop up on Monday, Tuesday and Wednesday, the NWS said.

Many Twin Cities residents noticed that the smell of smoke had returned to the metro area Thursday afternoon. That was because thunderstorms brought smoke from the upper levels of the atmosphere down to the surface, according to Hennepin County Emergency Management.

For other parts of Minnesota, an air-quality alert was issued due to the Greenwood fire, which continues to burn in the Superior National Forest, according to a news release from the Minnesota Pollution Control Agency.

The alert is effective until 9 a.m. Friday for Pine, Aitkin, Crow Wing, Kanabec, Chisago, Isanti, Benton, Morrison and Mille Lacs counties.

Another air-quality alert was in effect until 8 p.m. Friday for St. Louis, Carlton, Itasca, Koochiching, Lake and Cook counties.

Fine particles are expected to reach a level that is considered unhealthy for everyone across much of the areas covered by the alerts.

Alex Chhith • 612-673-4759